Gypsum bearing face material of wooden building, bearing wall structure, and bearing wall construction method

Abstract

To enlarge a wall magnification of a wooden bearing wall without mounting a reinforcer or a stiffener additionally and without increasing the specific gravity and / or board thickness of a gypsum face material.SOLUTION: A gypsum bearing face material for a wooden bearing wall comprises a main material or a core material constituting a tabular hardened gypsum body having an inorganic fiber and an organic strength improver so as to exert a nail lateral resistance equal to or greater than 500 N, and a paper member covering at least front and rear surfaces of the main material or the core material. This bearing face material has an area density in a range of 6.5-8.9 kg / m2, shows an ultimate displacement (δu2) greater than 20×10-3 rad in an in-plane shear test and exerts an ultimate strength (a correction value) (Pu') greater than 7.6 kN. The wooden bearing wall using this bearing face material can achieve a short period reference shear capacity (P0) greater than that of the wooden bearing wall using the same type of the bearing face material having the area density equal to or greater than 9.0 kg / m2.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a gypsum-based load-bearing board, a load-bearing wall structure, and a load-bearing wall construction method for a wooden construction building, and more specifically to a gypsum-based load-bearing board, a load-bearing wall structure, and a load-bearing wall construction method that are configured to increase the wall ratio without relying on increasing the maximum strength of the board itself or on the installation of additional reinforcing or stiffening materials. [Background technology]

[0002] In Japan, various construction methods for relatively small buildings, such as residential buildings, are known, including the long-established wooden frame construction method, the wooden frame wall construction method that has been popular since the 1970s, the steel frame construction method that has been popular since the 1960s, and the steel house construction method that has been gaining popularity in recent years. The wooden frame construction method, generally consisting of rectangular lumber assembling columns and beams to construct a wooden frame structure, is the most widely used traditional construction method in Japan. The wooden frame construction method, also known as the two-by-four construction method, is a "construction method in which walls and floor slabs are constructed by nailing structural plywood or similar materials to a wooden framework" (Ministry of Land, Infrastructure, Transport and Tourism Notifications No. 1540 and 1541, 2002). The steel frame construction method is a construction method in which steel members, such as columns, beams, and braces, are assembled to construct a steel frame structure. Conceptually, the steel house construction method is a structure in which the wooden framework of the wooden frame wall construction method is replaced with lightweight steel, and is a steel frame wall construction method stipulated in the "Thin Plate Lightweight Steel Construction" (Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1641, 2001). Other structures known for small buildings include rigid frame structures or wall-type reinforced concrete structures.

[0003] As such, a wide variety of structures are known as small-scale buildings in Japan, but below we will explain the earthquake resistance performance of wooden structure buildings as a technology related to the present invention.

[0004] Generally, construction methods for wooden buildings are broadly divided into wooden frame construction and wooden frame wall construction. Due to the impact of recent large-scale earthquakes, research into the seismic resistance of wooden buildings has been attracting particular attention in Japan in recent years. In architectural design practice in Japan, the effective frame length of a shear wall (the length of the wall in the architectural plan) is generally used as an indicator of the strength of a wooden building against short-term horizontal loads (seismic force, wind pressure, etc.) (Patent Document 1: JP 2001-227086 A). A wall factor appropriate to the structure of the shear wall is used to calculate the frame length. The wall factor is an indicator of the seismic or strength-bearing performance of the shear wall; the higher the factor, the greater the seismic strength. When a specific number of shear walls are to be used in a design, adopting a shear wall structure with a relatively high wall factor can improve the seismic resistance of the entire building. In Japan, wooden buildings require a wall volume required by the Building Standards Act to provide the required seismic resistance. The strength of a wooden building against short-term horizontal loads is proportional to the wall ratio of the shear wall multiplied by the wall length. In typical architectural design, a wall volume (frame length of the shear wall multiplied by the wall ratio) greater than the required wall volume must be ensured in both the span and longitudinal directions. Generally, adopting a shear wall structure with a relatively high wall ratio reduces the number of shear walls (number of installation locations) and improves the design flexibility of the entire building. Conversely, adopting a shear wall structure with a relatively low wall ratio increases the number of shear walls (number of installation locations), reducing the design flexibility of the entire building. Therefore, a wall structure with a high wall ratio is advantageous for improving the design flexibility and seismic resistance of the entire building.

[0005] The wall multiplier for general-purpose wooden shear walls, which have been used in Japan for many years, is specified in Article 46 of the Building Standards Act Enforcement Order and Ministry of Construction Notification No. 1100 (June 1, 1981). However, for many of the shear walls that have been constructed in recent years that do not fall under this general-purpose wall structure, the wall multiplier must be determined based on the certification of the Minister of Land, Infrastructure, Transport and Tourism as stipulated in Article 4, Table 1 (viii) of the same Act. Therefore, the wall multiplier for many wooden shear walls constructed in recent years must be determined based on performance tests conducted by designated performance evaluation organizations. The test methods for these performance tests are described in detail in documents such as the "Wooden Shear Walls and Their Multipliers: Performance Testing and Evaluation Procedures Manual" published by each testing and inspection organization.

[0006] As described in many publications, such as "Wooden Shear Walls and Their Multipliers: Performance Testing and Evaluation Procedure Manual," the performance test for determining the wall multiplier of wooden shear walls is an in-plane shear test. In this test, a predetermined horizontal load is repeatedly applied to a shear wall specimen, and the relationship between the horizontal load (P) and the shear deformation angle (δ) is determined. As described in many technical publications, such as "Allowable Stress Design for Wooden Frame Construction Houses [1] (2017 Edition)," pages 63 and 300 (Non-Patent Document 1), the wall multiplier is calculated by calculating the short-term allowable shear strength (Pa) based on the horizontal load and shear deformation angle, and then dividing this by the specified strength (wall length L (m) × 1.96 (kN / m)) (shown as a formula in Figure 5). Therefore, the wall multiplier is an indexed value obtained by dividing the short-term allowable shear strength (Pa) by this standard value (1.96L). Here, the short-term allowable shear strength (Pa), which is the basis for calculating the wall factor, is, in principle, the value obtained by multiplying the smallest value (i.e., short-term standard shear strength (P0)) among the following four indicators (values ​​obtained by multiplying each measurement value obtained in the in-plane shear test by each variation coefficient) by a specified reduction coefficient (α) (a coefficient that evaluates the factors that cause a decrease in strength). (1) Yield strength (Py) (2) The value of ultimate strength (Pu) corrected based on the ductility factor (μ) (hereinafter referred to as "ultimate strength (corrected value) (Pu')"). (3) 2 / 3 of the maximum strength (Pmax) (4) Strength when shear deformation angle = 1 / 120 rad (unloaded or loaded type)

[0007] On the other hand, "structural gypsum board" is known as a gypsum-based surface material that can be suitably used as a bearing surface material for wooden structural shear walls. "Structural gypsum board" is a gypsum board that has enhanced nail lateral resistance compared to "reinforced gypsum board" based on the applicant's technology described in Patent Publication No. 5642948 (Patent Document 3). Nail lateral resistance is the shear strength or shear capacity of the nailed portion of the surface material measured by the measurement method specified in JIS A 6901. Figure 6 is a perspective view for explaining the outline of the nail lateral resistance test. The nail lateral resistance test for determining nail lateral resistance is carried out according to JIS A As specified in JIS No. 6901, a 150 mm x 75 mm test piece 100 taken from the surface material to be tested was used, and a through hole 102 with a diameter of 2.6 mm was drilled at a position on the center line of the test piece 100 12 mm away from the edge 103 of one end (upper end) in the longitudinal direction of the test piece 100, and a steel round bar 101 (diameter 2.6 mm, length approximately 40 mm) was inserted into this through hole 102. In this test, the structural plane (center plane) of the test piece 100 is held generally vertical, the round bar 101 is held horizontal, the other longitudinal end (lower end) of the test piece is fixed, and a load FV is applied to the round bar 101, raising the round bar 101 at a rate of approximately 6 mm / min. As the round bar 101 displaces upward, a local load acts from the round bar 101 on the through hole 102 of the test piece 100, causing the test piece 100 to break. The nail lateral resistance value is the strength (load) at the time of breakage of the test piece 100. Note that a similar test for nail lateral resistance is also specified in ASTM, but in this application, the invention is defined based on the nail lateral resistance value obtained by the nail lateral resistance test method specified in JIS A 6901.

[0008] Currently, structural gypsum board is specified in JIS A 6901 as a gypsum-based surface material with a nail lateral resistance of 750N or more (Type A) or 500N or more (Type B). Generally, structural gypsum board requires a thickness of 12.5mm or more and a specific gravity of 0.75 or more. Therefore, a wooden structural wall with structural gypsum board fixed in place must have a specific gravity of at least 9.4kg / m. 2The surface density or surface weight (mass of load-bearing surface material per unit area of ​​wall) of 10 ...

[0009] Generally, the short-term standard shear strength (P0) of structural gypsum board is determined by the yield strength (Py) of the above four indices. As mentioned above, the wall factor is the short-term standard shear strength (P0) multiplied by the reduction coefficient (α) and then divided by the specified strength, so the wall factor of structural gypsum board is proportional to the yield strength (Py).

[0010] Structural gypsum board is a load-bearing surface material limited to installation on indoor walls, and its installation as a load-bearing surface material on the outdoor surface of a wooden exterior wall is not permitted. In contrast, Japanese Patent Publication No. 6412431 (Patent Document 2) discloses a gypsum board developed by the present applicant as a gypsum-based load-bearing surface material that can be installed on the outdoor surface of a wooden exterior wall, which contains an organopolysiloxane compound as a load-bearing deterioration inhibitor in the gypsum core. A gypsum board developed by combining the technology described in Patent Publication 2 with the technology described in Japanese Patent Publication No. 5642948 (Patent Document 3), which increases the shear resistance or shear strength of the nailed portion of the surface material, has already been put to practical use in Japan under the product name "Tiger EX Board" (registered trademark, product of Yoshino Gypsum Co., Ltd.). This gypsum board (hereinafter referred to as "EX board") has dimensions and weight of 9.5 mm thick, 910 mm wide, 3030 mm high, and approximately 26 kg. EX board requires a specific gravity of approximately 1.0 to obtain the desired maximum load (maximum strength (Pmax)) in an in-plane shear test. Therefore, a wooden structural shear wall to which EX board is fixed also requires a specific gravity of at least approximately 9.4 kg / m. 2 The surface density or surface weight is required.

[0011] The short-term standard shear strength (P0) of EX boards is determined by the ultimate strength (corrected value) (Pu') of the four indices above. This is because, as a result of the increase in the yield strength (Py), the ultimate strength (corrected value) (Pu') has become the smallest of the four indices above.

[0012] Specifically, the ultimate strength (corrected value) (Pu') is a value calculated using the formula below based on the ultimate strength (Pu) and plasticity factor (μ) measured by an in-plane shear test, and the short-term standard shear strength (P0) is a value calculated using the formula below based on the ultimate strength (corrected value) (Pu') and the coefficient of variation of the measurement values ​​(β). Pu' = Pu × 0.2 × (2μ-1) 1 / 2 P0 = β × Pu'

[0013] Therefore, while an increase in ultimate strength (Pu) is beneficial in increasing the wall ratio of shear walls, the ultimate strength (Pu) generally increases with an increase in the maximum load (Pmax) that the panel can withstand in an in-plane shear test, i.e., the maximum strength. For this reason, according to the knowledge and technical understanding of the inventors, past research and development aimed at increasing the short-term design shear strength (P0) of gypsum-based shear panels was primarily intended to increase the maximum load (Pmax) measured in an in-plane shear test, thereby indirectly increasing the ultimate strength (Pu), but was not intended to increase the ultimate strength (Pu) in relation to the ultimate displacement (δu) and ductility factor (μ).

[0014] In this specification, gypsum-based facing materials not specified in JIS A 6901 (gypsum board products) will be referred to as "gypsum board" regardless of whether they are gypsum-based facing materials in which the gypsum core portion (core portion) made primarily of gypsum is exposed on the outer surface or outer layer, or whether they are gypsum-based facing materials in which the outer surface or outer layer of the gypsum core portion is covered with gypsum board base paper.

[0015] In the aforementioned performance test for determining the wall factor of a wooden structural shear wall, the EX board exhibits maximum strength capable of withstanding a relatively high maximum load. However, after achieving the maximum load (maximum strength) at a specific shear deformation angle, slight increases in the shear deformation angle tend to cause punching out, edge breakage, cracking, etc., of the face material, resulting in a sudden drop in load or early shear failure (e.g., the comparative examples shown in Figures 4(A) and 5). As a result, the EX board suffers from a significant drop in ultimate strength (corrected value) (Pu') and a decrease in the wall factor. To address this issue, a face material reinforcement method is known in which reinforcing or stiffening materials, such as metal plates, are placed in nailed areas to prevent damage or fracture of the nailed areas, as a measure to increase the ultimate strength (corrected value) (Pu') and improve the wall factor (International Publication WO 2019 / 203148 A1 (Patent Document 4)). With wooden shear walls that use such reinforcing or stiffening materials, it is possible to improve the toughness and deformation compliance of the shear face material, increase the aforementioned ultimate strength (corrected value) (Pu'), and construct wooden shear walls that exhibit a relatively high wall multiplier, without relying on an increase in the maximum load that the face material can withstand in the above-mentioned performance test. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-227086 [Patent Document 2] Patent No. 6412431 Publication [Patent Document 3] Patent No. 5642948 Publication [Patent Document 4] International Publication WO2019 / 203148A1 [Non-patent literature]

[0017] [Non-Patent Document 1] Allowable Stress Design of Wooden Frame Construction Houses [1] (2017 Edition), pages 63 and 300 Summary of the Invention [Problem to be solved by the invention]

[0018] However, in the case of a bearing wall structure (Patent Document 4) that uses the above-mentioned reinforcing or stiffening material to increase the ultimate strength (corrected value) (Pu'), a process for additionally attaching the reinforcing or stiffening material to the surface of the bearing face material must be added to the face material manufacturing process, or such a process must be additionally performed during the construction of the wooden bearing wall. This type of process can complicate the manufacturing process of gypsum-based face materials or can be a factor that deteriorates the workability of construction work.

[0019] On the other hand, in order to improve the wall ratio of wooden shear walls that use gypsum-based face materials as the load-bearing face material without relying on such reinforcing or stiffening materials, it would be necessary to increase the specific gravity and / or thickness of the gypsum-based face material and increase the maximum load-bearing strength of the gypsum-based face material, but as mentioned above, the above-mentioned EX board weighs approximately 26 kg in its standard dimensions (approximately 910 mm wide and 3030 mm high).For this reason, considering the actual work that construction workers perform by hand to fix the load-bearing face material to the wall substrate of a wooden shear wall, it would be extremely difficult in practice to further increase the specific gravity and / or thickness of EX board or structural gypsum board, given the ease of construction of wooden shear walls.

[0020] The present invention was made in consideration of these problems, and its purpose is to provide a gypsum-based load-bearing surface material for wooden structural load-bearing walls that can increase the wall coefficient without additionally attaching reinforcing or stiffening materials and without increasing the specific gravity and / or thickness of the gypsum-based surface material.

[0021] Another object of the present invention is to provide a bearing wall structure for a wooden building using such a gypsum-based surface material as a bearing wall surface material, and a method for constructing a bearing wall.

[0022] Another object of the present invention is to provide a method for increasing the wall factor of a wooden structural shear wall, which can increase the wall factor without relying on the reinforcing or stiffening action of a reinforcing material or stiffening material additionally provided on the gypsum-based surface material, and without relying on an increase in the specific gravity and / or board thickness of the gypsum-based surface material. [Means for solving the problem]

[0023] In order to achieve the above object, the present invention provides a gypsum-based shear surface material for wooden structural shear walls, which is fastened to the wooden structural wall substrate of a wooden framework construction method or a wooden frame wall construction method with fasteners, The bearing surface material is composed of a main material or core material made of a plate-shaped gypsum hardened body blended with inorganic fibers and organic strength-improving materials so as to exhibit a nail side resistance of 500 N or more, and a paper member covering at least the front and back surfaces of the main material or core material. The surface density or surface weight, specified as the mass per unit area of ​​the wall, is 6.5 to 8.9 kg / m 2 and having an areal density or areal weight in the range of The ultimate displacement (δu2) of the shear wall measured by an in-plane shear test using a shear wall specimen with a wall length of 1.82 m is 20 × 10 -3 The ultimate displacement (δu2) of the shear wall is greater than rad. We provide a gypsum-based shear surface material (claim 13) characterized in that it produces a corrected value (Pu') of the ultimate strength (Pu) of the shear wall that is calculated based on the ultimate strength (Pu) and plasticity factor (μ) of the shear wall measured by the in-plane shear test, the corrected value (Pu') being greater than 7.6 kN.

[0024] According to the gypsum-based bearing surface material of the present invention, the minimum physical properties required for a gypsum-based bearing surface material (nail lateral resistance: 500 N or more) are ensured by mixing inorganic fibers and organic strength improving materials, while the surface density of the surface material is rather reduced to a relatively low value (6.5 to 8.9 kg / m 2 In the following description of this specification, the term "minimum physical properties" means a nail side resistance of 500 N or more.

[0025] The above surface density values ​​(6.5 to 8.9 kg / m 2 ) is the surface density of structural gypsum board and EX board (approximately 9.4 kg / m 2 ), and therefore, this contradicts the conventional method of increasing the short-term design shear strength (P0) (i.e., increasing the maximum strength (maximum load (Pmax)) by increasing the specific gravity and / or thickness, thereby increasing the short-term design shear strength (P0)). Under the conventional concept of increasing the wall factor, this configuration was assumed to result in a decrease in the wall factor. However, the inventors' experiments have shown that if the areal density is reduced while maintaining the minimum physical properties required for gypsum-based shear panels (nail lateral resistance: 500 N or more), the inherent toughness and deformation compliance of gypsum-based shear panels become apparent, resulting in an increase in the ultimate displacement (δu) and ductility factor (μ), which in turn increases the ultimate strength (corrected value) (Pu'). Therefore, it is possible to increase the short-term design shear strength (P0) without necessarily increasing the maximum strength (maximum load (Pmax)). As mentioned above, the short-term standard shear strength (P0) is proportional to the wall factor. Therefore, an increase in the ultimate displacement (δu) and ductility factor (μ), which result in an increase in the short-term standard shear strength (P0), is an effective factor in increasing the wall factor. Thus, the gypsum-based shear face material of the present invention ensures the minimum physical properties required for a gypsum-based shear face material. By improving the toughness and deformation compliance of the gypsum-based shear face material and increasing the ultimate strength (corrected value) (Pu'), the wall factor can be increased without additional reinforcement or stiffening materials, and without increasing the specific gravity and / or thickness of the gypsum-based shear face material. Furthermore, like structural gypsum board and EX board, the above-mentioned shear face material has at least the front and back surfaces of the main or core material covered with paper members, allowing it to be easily manufactured on conventional gypsum board production lines. The "front and back surfaces" refer to the front and back surfaces of the face material excluding the end faces or side surfaces of the end and side edges (i.e., the four outer edges) of the face material.

[0026] Preferably, the thickness of the gypsum-based bearing surface material is set to a value less than 12 mm (more preferably, 10 mm or less (8.5 mm or more)), for example, 9.5 mm or 9.0 mm. Gypsum-based bearing surface materials with such a thickness are advantageous in terms of reducing the wall thickness of wooden structural bearing walls, compared to structural gypsum boards that require a thickness of 12 mm or more. Optionally, the gypsum hardened body has a nail lateral resistance of 980 N or less.

[0027] Preferably, the specific gravity of the gypsum-based bearing surface material is set to 0.96 or less (0.65 or more), preferably 0.9 or less (more preferably 0.8 or less). A gypsum-based bearing surface material with such a specific gravity allows the surface material to be lighter than an EX board, which has a specific gravity of 1.0 or more, and is therefore advantageous in reducing the weight of wooden bearing walls or improving the workability of wooden bearing walls or the workability of their construction.

[0028] In a preferred embodiment of the present invention, the core material (gypsum core portion) of the gypsum-based load-bearing facing material contains an organopolysiloxane compound as a load-bearing deterioration inhibitor to prevent load-bearing deterioration. This load-bearing facing material can be applied to the exterior wall surface of a wooden exterior wall, similar to EX boards.

[0029] The present invention also provides a wooden structural shear wall (claim 1) having a structure in which the above-mentioned gypsum-based shear face material is fastened to the wooden structural wall substrate of a wooden frame construction method or a wooden frame wall construction method with fasteners such as nails or screws. Such a wooden structural shear wall improves the toughness and deformation followability of the gypsum-based shear face material, thereby increasing the short-term standard shear strength (P0), and reduces the specific gravity and / or thickness of the gypsum-based shear face material, thereby making it possible to reduce the weight of the shear wall or the wall thickness. The ultimate displacement (δu) obtained by an in-plane shear test of such a shear wall structure is at least 20 × 10 -3 rad, preferably 22×10 -3rad or more, and the toughness and deformation followability of such a displacement amount can be obtained. In addition, in the "Wooden shear walls and their multiplier performance test and evaluation procedure manual", if the load does not decrease even when it exceeds 1 / 15 rad in the in-plane shear test and the value of the ultimate displacement cannot be obtained, the ultimate displacement (δu) is set to 1 / 15 rad. Therefore, the maximum value of the ultimate displacement (δu) is 1 / 15 rad (66.7 x 10 -3 rad).

[0030] The present invention further provides a construction method for wooden structural shear walls (claim 5), characterized in that the above-mentioned gypsum-based shear face material is fastened to the wooden structural wall substrate of a wooden frame construction method or a wooden frame wall construction method using the above-mentioned fasteners. This construction method for shear walls improves the toughness and deformation compliance of the gypsum-based shear face material, increasing the short-term standard shear strength (P0), and reduces the specific gravity and / or thickness of the gypsum-based shear face material, thereby making it possible to reduce the weight of the shear wall, improve the construction ease of the shear wall, or reduce the wall thickness. In an in-plane shear test of a shear wall structure constructed using this construction method, the shear wall has a strength of at least 20 x 10 -3 Ultimate displacement (δu) greater than the value of rad, preferably 22 × 10 -3 The ultimate displacement (δu) is equal to or greater than 1 / 4 rad, and therefore the shear wall has the toughness and deformation compliance corresponding to the ultimate displacement (δu).

[0031] From another perspective, the present invention provides a method for increasing the wall strength of a wooden structural shear wall constructed by fastening a gypsum-based shear face material to a wooden structural wall substrate of a wooden frame construction method or a wooden frame wall construction method with fasteners, The load-bearing surface material is composed of a main material or core material made of a plate-shaped gypsum hardened body blended with inorganic fibers and organic strength-improving materials so as to exhibit a nail side resistance of 500 N or more, and a paper member covering at least the front and back surfaces of the main material or core material, The surface density or surface weight of the bearing surface material, specified as the mass per unit area of ​​the wall surface, is 6.5 to 8.9 kg / m 2 reduced to The ultimate displacement (δu2) of the shear wall measured by an in-plane shear test using a specimen with a wall length of 1.82 m was calculated as 20 × 10 -3 Ensure that the ultimate displacement (δu2) is greater than rad. The wall factor increasing method (claim 9) is characterized in that a corrected value (Pu') of the ultimate strength (Pu) calculated based on the ultimate strength (Pu) and the plasticity factor (μ) of the bearing wall measured by the in-plane shear test is secured to be greater than 7.6 kN.

[0032] Preferably, the thickness of the gypsum-based load-bearing surface material is set to a value less than 12 mm (more preferably, 10 mm or less (8.5 mm or more)), for example, 9.5 mm or 9.0 mm, and the specific gravity of the gypsum-based surface material is set to a value of 0.96 or less (0.65 or more) (more preferably, 0.8 or less). [Effects of the Invention]

[0033] According to the gypsum-based load-bearing facing material of the present invention, the toughness and deformation compliance of the gypsum-based facing material are improved by reducing the areal density, thereby increasing the ultimate strength (corrected value) (Pu') and the short-term standard shear strength (P0). Therefore, the wall ratio can be increased without attaching additional reinforcing or stiffening materials and without increasing the specific gravity and / or board thickness of the gypsum-based facing material. Moreover, since the gypsum-based load-bearing facing material of the present invention has at least the front and back surfaces of the main material or core material covered with paper members, it can be easily manufactured on a conventional gypsum board manufacturing line.

[0034] Furthermore, according to the load-bearing wall structure of the wooden structure building of the present invention, the wall coefficient can be increased, and the specific gravity and / or thickness of the gypsum-based load-bearing surface material can be reduced, thereby reducing the weight of the load-bearing wall or the wall thickness.

[0035] Furthermore, according to the method for constructing shear walls for wooden structure buildings of the present invention, not only can the wall ratio be increased, but the specific gravity and / or thickness of the gypsum-based shear wall material can be reduced, thereby reducing the weight of the surface material and improving the workability of the shear wall.

[0036] Furthermore, according to the method for increasing the wall factor of the present invention, by reducing the surface density while ensuring the minimum physical properties (nail side resistance = 500 N or more) of a gypsum-based load-bearing surface material, it is possible to improve the toughness and deformation compliance of the gypsum-based surface material while ensuring a certain level of maximum strength (maximum load), thereby increasing the ultimate strength (corrected value) (Pu').Therefore, the wall factor can be increased without relying on reinforcement or stiffening by additional reinforcing or stiffening materials installed on the gypsum-based surface material, or without relying on an increase in the specific gravity and / or thickness of the gypsum-based surface material. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a front view showing a schematic configuration of a bearing wall of a wooden building. [Figure 2] FIG. 2 is a front view showing the configuration of a shear wall specimen used in an in-plane shear test on the shear wall structure shown in FIG. [Figure 3] FIG. 3 is a table showing the physical properties and compositions of gypsum boards according to examples of the present invention and comparative examples. [Figure 4] FIG. 4 is a diagram showing the load-deformation angle curve obtained by the in-plane shear test, in which FIG. 4(A) shows the in-plane shear test result of the gypsum board according to the comparative example, and FIG. 4(B) shows the in-plane shear test result of the gypsum board according to the embodiment of the present invention. [Figure 5] FIG. 5 is a diagram showing an envelope curve created based on the load-deformation angle curve shown in FIG. [Figure 6] FIG. 1 is a perspective view showing an outline of the nail lateral resistance test specified in JIS A 6901. DETAILED DESCRIPTION OF THE INVENTION

[0038] Hereinafter, the configuration of a load-bearing wall according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0039] FIG. 1 is a front view showing a schematic configuration of a bearing wall of a wooden building.

[0040] The bearing wall 1 shown in FIG. 1 is a wooden frame construction bearing wall constructed by fixing a bearing face panel 10 to a wooden frame on a continuous footing F of a reinforced concrete (RC) structure. The bearing face panel 10 has dimensions of 9.5 mm thick, 910 mm wide, and approximately 2800 to 3030 mm (for example, 2900 mm) high, and has a strength of 6.5 to 8.9 kg / m 2 areal density within the range (e.g., areal density 7.1 kg / m 2 ). The areal density (also called areal weight) is the mass (weight) per unit area of ​​the wall surface when viewed from the front. The load-bearing surface material 10 is a gypsum-based surface material composed of a flat gypsum core (gypsum core material) mixed with a predetermined amount of inorganic fiber (glass fiber) and organic strength-enhancing material (starch), and gypsum board base paper (paper component) covering both sides of the gypsum core.

[0041] The bearing wall 1 has a base 2 fixed to the top surface of a continuous footing F with anchor bolts B. The bearing wall 1 is generally composed of this base 2, columns 3, partition studs 4, and inter-joint columns 4' arranged vertically at predetermined intervals on the base 2, horizontal cross members (beams, girths, eaves beams, gable beams) 5 supported on the upper ends (or middle parts) of the columns 3, and the above-mentioned bearing surface material 10. The base 2, columns 3, partition studs 4, inter-joint columns 4', and beams 5 that make up the framework are made of wood (square timber) with the cross-sections used in ordinary wooden buildings.

[0042] The bearing surface panel 10 is fixed to the sill 2, columns 3, studs 4, inter-joint columns 4', and cross members 5 by nails 20. The nails 20 are, for example, galvanized iron round nails (NZ nails: JIS A 5508). In this example, NZ50 nails (length 50 mm, head diameter approximately 6.6 mm, shank diameter approximately 2.75 mm) are used as the nails 20. The nails 20 are arranged at intervals S1 in the four outer peripheral zones of the bearing surface panel 10, and at intervals S2 in the central zone of the bearing surface panel 10 extending in the vertical direction. Preferably, the interval S1 is set to a dimension within a range of 50 mm to 200 mm (e.g., 75 mm), and the interval S2 is set to a dimension within a range of 50 mm to 300 mm (e.g., 150 mm).

[0043] The gypsum core (core material) of the bearing surface material 10 contains a predetermined amount of inorganic fibers and an organic strength-enhancing material and has a nail side resistance of 500 N or more. The amount of inorganic fibers is 0.3 to 5 parts by weight, preferably 2 to 4 parts by weight, per 100 parts by weight of calcined gypsum. Examples of inorganic fibers to be added include glass fiber and carbon fiber. When glass fiber is used, glass fiber having a diameter of 5 to 25 μm and a length of 2 to 25 mm can be preferably used. The amount of organic strength-enhancing material to be added is 0.3 to 15 parts by weight, preferably 1 to 13 parts by weight, per 100 parts by weight of calcined gypsum. Examples of organic strength-enhancing materials to be added include starch, polyvinyl acetate, polyvinyl alcohol, and polyacrylic. Both unmodified and modified starches can be used as the starch. Examples of modified starches include starches that have been subjected to physical, chemical, or enzymatic treatment. As the physically treated starch, pregelatinized starch can be preferably used, and as the chemically treated starch, oxidized starch, phosphated starch, urea phosphated starch, hydroxyethylated starch, hydroxypropylated starch, and acetylated starch can be preferably used.

[0044] The composition and structure of the bearing surface material 10 are similar to those of the "structural gypsum board" specified in JIS A 6901. However, the surface density of the bearing surface material 10 is 6.5 to 8.9 kg / m 2 A value within the range (e.g., 7.1 kg / m 2 ) Therefore, the bearing surface material 10 has a strength of 9.4 kg / m as mentioned above. 2 This differs fundamentally from the "structural gypsum board" specified in JIS A 6901, which requires an areal density of 9.4 kg / m or more. Also, "reinforced gypsum board" specified in JIS A 6901 is known, but "reinforced gypsum board" also has an areal density of 9.4 kg / m. 2Since the load-bearing surface material 10 requires an area density of 500 N or more, it is fundamentally different from "reinforced gypsum board." The load-bearing surface material 10 also differs from other "gypsum boards" in that it has a main or core material that is a blend of inorganic fiber and organic strength-enhancing material to provide a nail side resistance of 500 N or more. In other words, the load-bearing surface material 10 does not fall under any of the "gypsum boards" specified in the current JIS A 6901. In this sense, the load-bearing surface material 10 will be specified or expressed as a "gypsum-based surface material" or "gypsum board" in this specification.

[0045] Generally, gypsum-based facing materials (including "gypsum board") are manufactured using a general-purpose gypsum board manufacturing apparatus. As described in International Publication WO2019 / 058936, for example, the gypsum board manufacturing apparatus has a mixer that prepares a gypsum slurry by mixing raw materials such as calcined gypsum, adhesive aids, hardening accelerators, and foam (or foaming agents) with mixing water required to form a slurry of the calcined gypsum. The gypsum slurry is poured and spread onto gypsum board base paper (bottom paper) on the conveyor belt of the gypsum board manufacturing apparatus, and the gypsum board base paper (top paper) is laminated on the gypsum slurry. The resulting continuous band-shaped laminate with a three-layer structure is processed using various devices that make up the gypsum board manufacturing apparatus, such as a rough cutting device, a forced drying device, and a cutting device, to form a gypsum product of a predetermined size, i.e., a gypsum-based facing material in which both sides of a hardened gypsum slurry body (i.e., a gypsum core) are covered with gypsum board base paper. The specific gravity of gypsum-based facings is primarily controlled by the amount of foam in the gypsum slurry.

[0046] Regarding wooden structural shear walls that use structural gypsum board, reinforced gypsum board, and (ordinary) gypsum board as the load-bearing surface material as specified in JIS A 6901, examples of wall coefficients for shear walls made of large wooden frame structures as specified in the aforementioned Ministry of Construction Notification No. 1100 are as follows: Structural gypsum board (Type A) 1.7 Structural gypsum board (Type B) 1.2 Reinforced gypsum board 0.9 (Normal) Gypsum board 0.9

[0047] In addition, examples of wall coefficients for frame wall construction shear walls (shear walls with a vertical frame spacing of more than 50 cm) specified in the aforementioned Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1541 are as follows: Structural gypsum board (Type A) 1.7 Structural gypsum board (Type B) 1.5 Reinforced gypsum board 1.3 (Normal) Gypsum board 1.0

[0048] As such, the wall coefficient values ​​specified in notifications from the Ministry of Construction or the Ministry of Land, Infrastructure, Transport and Tourism are values ​​that can generally be adopted without conducting individual performance tests, but when using new materials or adopting a different wall coefficient, it is necessary to conduct the aforementioned performance tests and determine the wall coefficient value.

[0049] As mentioned above, the structural gypsum board and reinforced gypsum board specified in JIS A 6901 have an areal density of 9.4 kg / m 2 The surface density and specific gravity must be 0.75 or more. This is considered to be an important condition for increasing the maximum load that the surface material can withstand and for ensuring high short-term allowable shear strength (and therefore high wall ratio) for wooden structural shear walls. In particular, for structural gypsum board, which must exhibit higher nail lateral resistance than reinforced gypsum board, it has been thought that such surface density and specific gravity cannot be reduced. That is, a surface density of 9.4 kg / m 2As mentioned above, ensuring a specific gravity of 0.75 or higher was considered essential for further increasing the wall strength of shear wall specimens (wooden shear walls) obtained in the aforementioned in-plane shear tests. However, recent experiments by the present inventors and others have revealed that in gypsum-based facings that have properties (nail lateral resistance) comparable to those of structural gypsum boards by adding inorganic fibers or organic strength enhancers, reducing the thickness of the facing or adjusting the foam content to reduce the specific gravity of the gypsum core, thereby reducing the areal density, reveals the inherent toughness or deformation compliance of the facing. This effectively utilizes the ultimate strength of the facing and increases the ductility of the facing, thereby further improving the short-term allowable shear strength of wooden shear walls. The present inventors have conceived the present invention based on the findings obtained through such experiments. The following describes in detail the experiments (in-plane shear tests) conducted by the present inventors and others.

[0050] Figure 2 is a front view showing the configuration of the shear wall specimen used in the in-plane shear test on the shear wall structure shown in Figure 1. Figures 3 to 5 are diagrams and charts showing the test results of the in-plane shear test. In Figure 2, the same reference numerals are used to designate the components or components of the shear wall specimen that correspond to or correspond to the components or components shown in Figure 1.

[0051] In accordance with the specimen specifications described in the "Wooden Shear Walls and Their Magnification Factors Performance Testing and Evaluation Procedure Manual," the inventors fabricated a shear wall specimen (hereinafter simply referred to as "specimen") with a wall width of 1,820 mm and a height of 2,730 mm having the shear wall structure shown in Figure 2 as a specimen for the shear wall structure shown in Figure 1, and conducted an in-plane shear test using an unloaded caustic testing device.

[0052] The specimen shown in Figure 2 has a wooden frame structure consisting of a 105 x 105 mm cross-section cedar sill 2 and column 3, and a 180 x 105 mm cross-section Douglas fir cross member 5 supported by the column 3. A 45 x 105 mm cross-section cedar inter-column 4' is erected in the center between the columns 3, and a 27 x 105 mm cross-section cedar stud 4 is erected between the column 3 and the inter-column 4'. Cedar or Douglas fir ties 5' are installed between the column 3 and the stud 4, and between the stud 4 and the inter-column 4'. A pull-out metal fitting 40 is installed as a test fixture at the joint between the sill 2 and column 3, and at the joint between the cross member 5 and the column 3. The base 2, columns 3, joint columns 4', partitions 4, cross members 5 and cross ties 5' constitute the axial members of the load-bearing wall structure, and these members (axial members) form a rectangular framework.

[0053] In the specimen shown in Figure 2, the vertical distance h1 between the base 2 and the beam 3, the height h2 of the junction 5', and the relative height h3 of the beam 3 relative to the junction 5' were set to h1 = 2625 mm, h2 = 1790 mm, and h3 = 835 mm, respectively. The distance w1 between the column 3 and the joint column 4' (column center distance) was set to w1 = 910 mm, and the wall length L was set to 1.82 m. The panel 10 was divided into upper and lower sections by the junction 5'. The lower panel 10a had dimensions of 910 mm wide and 1820 mm high, and the upper panel 10b had dimensions of 910 mm wide and 865 mm high. The overlap dimensions h4 and h5 of the panels 10a and 10b were set to 30 mm.

[0054] In the test specimen shown in Figure 2, the nails 20 used to fasten the face panels 10a, 10b to the sill 2, columns 3, joint columns 4', cross members 5, and cross ties 5' were arranged at equal intervals (interval S1 = 75 mm) around the entire periphery of the edge zones of the face panels 10a, 10b. The nails 20 used to fasten the face panels 10a, 10b to the studs 4 were arranged at equal intervals (interval S2 = 150 mm) in the vertical center zones of the face panels 10a, 10b. NZ50 nails (length 50 mm, head diameter approximately 6.6 mm, shank diameter approximately 2.75 mm) were used as nails 20.

[0055] The inventors fabricated gypsum boards according to Examples 1 to 5 and the Comparative Example shown in the table of Fig. 3 as specimens and conducted in-plane shear tests using a non-loading caustic testing apparatus. As described above, the gypsum boards of Examples 1 to 5 are gypsum-based facing materials composed of a flat gypsum core (gypsum core material) mixed with a predetermined amount of inorganic fiber (glass fiber) and organic strength-enhancing material (starch), and gypsum board base paper (paper component) covering both sides of the gypsum core. The facing material of the Comparative Example is a gypsum board equivalent to the aforementioned EX board (board thickness 9.5 mm), and is a gypsum-based facing material composed of a flat gypsum core (gypsum core material) mixed with an amount of inorganic fiber (glass fiber) and organic strength-enhancing material (starch) equivalent to or less than the gypsum boards of Examples 1 to 5, and gypsum board base paper (paper component) covering both sides of the gypsum core. As shown in FIG. 3, the gypsum boards of Examples 1 to 5 had a compressive strength of 7.3 to 8.7 kg / m 2 The gypsum board of the comparative example has an areal density within the range of 9.8 kg / m 2 It has an areal density of

[0056] The ultimate displacement δu2 of the gypsum boards of Examples 1 to 5 obtained by the in-plane shear test was 26.8 × 10 -3 rad~36.0×10 -3 rad, and the ultimate displacement δu1 of the gypsum board of the comparative example obtained by the in-plane shear test was 20.0 × 10 -3rad. As shown in Fig. 3, in the gypsum boards of Examples 1 to 5 and the Comparative Example, the yield strength Py was greater than the ultimate strength (corrected value) Pu', so the short-term standard shear strength P0 and the wall magnification were determined by the ultimate strength (corrected value) Pu'. In the case of the gypsum boards of Examples 1 to 5, the ultimate strength (corrected value) Pu' was greater than that of the gypsum board of the Comparative Example, and the difference between the yield strength Py and the ultimate strength (corrected value) Pu' was less than 2.0 kN (1.6 or less), and a tendency for the difference between the yield strength Py and the ultimate strength (corrected value) Pu' to be relatively small was also observed. That is, as far as the test results shown in FIG. 3 are concerned, in both the comparative example and Examples 1 to 5, the ultimate strength (corrected value) Pu' is relatively smaller than the yield strength Py, but in Examples 1 to 5, the difference between the yield strength Py and the ultimate strength (corrected value) Pu' is reduced, and a tendency for the two to be numerically equalized is observed. The strength (load) and displacement (shear deformation angle) of each gypsum board of Examples 1 to 5 obtained by the in-plane shear test have substantially the same tendency or characteristics, so that the approximate intermediate ultimate displacement (33.1 × 10 -3 The properties of the gypsum board of the present invention will be explained below based on the test results of the gypsum board of Example 1, which showed a strength of 1000 MPa (rad).

[0057] Fig. 4 is a diagram showing the load-deformation angle curve obtained by an in-plane shear test. Fig. 4(A) shows the results of the in-plane shear test of the gypsum board according to the comparative example, and Fig. 4(B) shows the results of the in-plane shear test of the gypsum board of Example 1. Fig. 5 is a diagram showing an envelope curve created based on the load-deformation angle curve shown in Fig. 4. The envelope curve is a characteristic line of the load (yield strength) and displacement (shear deformation angle) based on the load-deformation angle curve of the side that was finally destroyed.

[0058] As shown in FIG. 4(A), the gypsum board of the comparative example has a deformation angle of approximately 20×10 -3The maximum load (maximum strength) Pmax was reached at rad, but the subsequent horizontal load applied immediately thereafter essentially caused failure, resulting in the load (strength) of the gypsum-based surface material immediately dropping to a value below 0.8Pmax. In Figure 4(A), the load level of the maximum load Pmax is shown by a dashed line, and the load level of the load drop region at 0.8Pmax is shown by a dashed double-dashed line. In Figure 4(A), the load-deformation angle curve during repeated loading immediately after the maximum load Pmax is shown below the load level of 0.8Pmax indicated by the dashed double-dashed line. This curve is determined by the load difference ΔP from the 0.8Pmax load level.

[0059] As shown in Fig. 4(A) and Fig. 5, in the case of the gypsum board of the comparative example, the deformation angle when the maximum load Pmax is applied is about 20 × 10 -3 Because the gypsum board fails suddenly at rad, the ultimate displacement δu1 essentially coincides with the deformation angle at the maximum load Pmax. Therefore, the short-term allowable shear strength of a gypsum board cannot be increased by relying solely on its toughness or deformation compliance. To increase the short-term allowable shear strength of a gypsum board, increasing its areal density and increasing the maximum load was considered the only practical method for increasing the wall factor. However, as is clear from the load-deformation curves of Example 1 shown in Figures 4(B) and 5, reducing the areal density while maintaining the minimum physical properties required for a gypsum-based load-bearing surface material (nail lateral resistance: 500 N or more) reveals the inherent toughness or deformation compliance of the gypsum board itself. As a result, it becomes possible to determine the short-term standard shear strength P0 based on the ultimate strength Pu and the plasticity factor μ. This point will be further explained below.

[0060] As shown in FIG. 4(B), the gypsum board of Example 1 had a deformation angle of about 20×10 -3 After reaching the maximum load (maximum strength) Pmax at rad, the deformation angle in the 0.8Pmax load drop region, i.e., the ultimate displacement δu2, is 33.1×10 -3 As described above, the ultimate displacement δu2 of each of the gypsum boards in Examples 1 to 5 was 26.8 × 10 -3 rad~36.0×10 -3The values ​​were within the range of rad, and in Examples 2 to 5, the ultimate displacement δu2 was approximately the same as that in Example 1. That is, the gypsum boards in Examples 1 to 5 had a deformation angle of approximately 20 × 10 -3 After reaching the maximum load (maximum strength) Pmax at rad, plastic deformation continued with subsequent repeated loading until the deformation angle reached approximately 1.3 to 1.8 times the deformation angle at the maximum load Pmax, and therefore the plasticity factor μ increased relatively significantly.

[0061] As explained at the beginning of this document, the wall factor is the short-term allowable shear strength Pa divided by a predetermined reference strength value (L × 1.96). The short-term allowable shear strength Pa is calculated by multiplying the short-term reference shear strength P0 by a predetermined reduction coefficient α, as can be seen from the formula shown in Figure 5. As with many past in-plane shear tests of gypsum-based surface materials, the short-term reference shear strength P0 of each example and comparative example is determined by multiplying the corrected value Pu' of the ultimate strength Pu obtained by correction based on the plasticity factor μ (i.e., the ultimate strength (corrected value) Pu') by a variation coefficient β. Therefore, as can be easily seen from the formula in Figure 5, the short-term reference shear strength P0 is proportional to the value of the ultimate strength Pu and increases with an increase in the plasticity factor μ. The ductility factor μ is proportional to the ultimate displacement δu, and assuming that the yield displacement δv is roughly the same value, the short-term design shear strength P0 increases as the ultimate displacement δu increases. In other words, the short-term design shear strength P0 can be increased by increasing the ultimate displacement δu. To simplify the explanation, the variation coefficient β is assumed to be 1.0.

[0062] As shown in the table in Figure 5, the short-term standard shear strength P0 obtained with the gypsum board of Example 1 is significantly greater than the short-term standard shear strength P0 obtained with the gypsum board of the comparative example. This means that a decrease in areal density increases the ultimate displacement δu2, thereby increasing the short-term standard shear strength P0 and, as a result, the wall factor. The reduction coefficient α is an artificially set value. The short-term allowable shear strength (Pa) is obtained by multiplying the short-term standard shear strength P0 by the reduction coefficient α, thereby obtaining the final wall factor. For example, if the reduction coefficient is set to 0.75, the wall factor of the wooden structural shear wall using the gypsum board of Example 1 is 2.25, which is approximately 1.4 times the wall factor (1.60) of the comparative example. This wall factor value is significantly greater than the wall factor of wooden structural shear walls using structural gypsum boards and the like specified in Ministry of Construction Notification No. 1100 and other regulations (the aforementioned wall factor of 0.9 to 1.7).

[0063] As explained above, in the bearing wall 1 having the above-described configuration, the bearing surface material 10 is composed of a main material or core material made of a plate-shaped gypsum hardened body blended with inorganic fiber and an organic strength-improving material so as to exhibit a nail side resistance of 500 N or more, and a paper member covering at least the front and back surfaces of the main material or core material. The surface density or surface weight of the bearing surface material 10, specified as the mass per unit area of ​​the wall surface, is 6.5 to 8.9 kg / m 2 The ultimate displacement δu2 of the shear wall 1 obtained by an in-plane shear test using a shear wall specimen with a wall length of 1.82 m is, for example, 33.1 × 10 -3 rad (Example 1), and 20 × 10 -3rad (Comparative Example), and the ultimate strength (corrected value) Pu' obtained by this in-plane shear test is, for example, 10.7 kN (Example 1), which is greater than 7.6 kN (Comparative Example).Assuming that the variation coefficient β = 1, the short-term allowable shear strength Pa is, for example, 10.7 kN (Example 1), which is greater than 7.6 kN (Comparative Example), and the wall factor is, for example, 2.25 (Example 1), which is greater than 1.60 (Comparative Example). Thus, with a bearing wall 1 having a structure in which the bearing surface panel 10 is fastened with nails 20 to the wooden wall base of a wooden frame construction method, the minimum physical properties required for a gypsum-based bearing surface panel (nail lateral resistance = 500 N or more) are ensured, while the toughness and deformation compliance of the gypsum-based bearing surface panel are improved to increase the ultimate strength (corrected value) Pu', thereby increasing the short-term standard shear strength P0 and the wall factor without attaching additional reinforcing or stiffening materials or increasing the specific gravity and / or thickness of the bearing surface panel 10.

[0064] The above describes in detail preferred embodiments and examples of the present invention, but it goes without saying that the present invention is not limited to the above embodiments and examples, and various modifications and changes are possible within the scope of the present invention described in the claims.

[0065] For example, although the above embodiments and examples relate to bearing walls at the first floor level of a wooden building, the present invention can be similarly applied to bearing walls at the second or third floor level. In the case of bearing walls at the second or third floor level, the lower end of the bearing face material is fastened to a cross member or the like at the second or third floor level.

[0066] Furthermore, while the above embodiments and examples relate to a wooden frame construction and large-wall construction load-bearing wall structure, the present invention may also be applied to a wooden frame construction and large-wall construction load-bearing wall structure, either a wooden frame construction with a solid wall or a floor-first (floor-first) and large-wall construction. As a modified example, the present invention may also be applied to a wooden frame construction and load-bearing wall structure, in which case the load-bearing face material is fastened to the vertical frame, lower frame, upper frame, etc. instead of the foundation, columns, and cross members.

[0067] Furthermore, while the specimen shown in Figure 4 is constructed by dividing the gypsum board into upper and lower halves and arranging a tether at the midpoint in the height direction, it is also possible to conduct in-plane shear tests using gypsum boards with a height dimension substantially equal to the total height of the wooden framework. In the latter case, it is believed that the short-term design shear strength can be further increased.

[0068] Furthermore, in the above embodiments and examples, the load-bearing surface materials are fastened to the wooden framework such as pillars and cross members with nails, but the load-bearing surface materials may also be fastened to the wooden framework with other types of fasteners such as screws. [Industrial Applicability]

[0069] The present invention is applicable to gypsum-based shear panels for wooden buildings. In particular, the present invention is applicable to gypsum-based shear panels having, as their main or core material, a plate-shaped gypsum hardened body containing inorganic fibers and organic strength-enhancing materials so as to exhibit a nail side resistance of 500 N or more. The present invention is also applicable to a method for increasing the wall strength factor of a wooden shear wall using such gypsum-based shear panels. The present invention is further applicable to a shear wall structure and a shear wall construction method for a wooden building, in which such gypsum-based shear panels are fastened to a wooden wall substrate for a wooden frame construction method or a wooden framework construction method, and the shear wall is structurally held integrally by the wooden wall substrate. According to the present invention, the wall strength factor of a wooden shear wall can be increased without additionally attaching reinforcing or stiffening materials or increasing the specific gravity and / or thickness of the gypsum-based shear panel, and therefore its practical value and effectiveness are remarkable. [Explanation of symbols]

[0070] 1 Load-bearing wall 2. Foundation 3 Pillars 4 studs 4' Joint Column 5. Horizontal members (beams, girder beams, eaves beams, gable beams) 5' Jumpsuit 10, 10a, 10b Gypsum-based load-bearing surface material 20 Nails (fasteners)

Claims

1. In a wooden structural shear wall having a structure in which a gypsum-based shear surface material is fastened to the wooden structural wall base of a wooden framework construction method or a wooden frame wall construction method by fasteners, The bearing surface material is composed of a main material or core material made of a plate-shaped gypsum hardened body blended with inorganic fibers and organic strength improving materials so as to exhibit a nail side resistance of 500 N or more, and a paper member covering at least the front and back surfaces of the main material or core material. The surface density or surface weight of the bearing surface material, specified as the mass per unit area of ​​the wall surface, is 6.5 to 8.9 kg / m 2 and having an areal density or areal weight in the range of The ultimate displacement (δu2) of the bearing wall measured by an in-plane shear test using a bearing wall specimen with a wall length of 1.82 m is 20 × 10 -3 has an ultimate displacement (δu2) greater than rad, A wooden structural shear wall characterized in that the corrected value (Pu') of the ultimate strength (Pu) calculated based on the ultimate strength (Pu) and plasticity factor (μ) of the shear wall measured by the in-plane shear test is greater than 7.6 kN.

2. 2. The wooden structural shear wall according to claim 1, wherein the yield strength (Py) measured by the in-plane shear test is greater than 7.6 kN.

3. 3. A wooden structural shear wall according to claim 1 or 2, characterized in that the corrected value (Pu') of the ultimate strength (Pu) is 8.0 kN or more, or the measured value (Py) of the yield strength of the shear wall measured by the in-plane shear test is 8.0 kN or more, or both the corrected value (Pu') and the measured value (Py) are 8.0 kN or more.

4. A wooden structural shear wall according to any one of claims 1 to 3, characterized in that the thickness of the gypsum-based load-bearing surface material is set to a value less than 12 mm, or the specific gravity of the gypsum-based load-bearing surface material is set to a value of 0.96 or less, or the thickness of the gypsum-based load-bearing surface material is set to a value less than 12 mm and the specific gravity of the gypsum-based load-bearing surface material is set to a value of 0.96 or less.

5. In a construction method for wooden structural shear walls, a gypsum-based shear surface material is fixed to the wooden structural wall substrate of a wooden framework construction method or a wooden frame wall construction method, The main or core material is a plate-shaped gypsum hardened body containing inorganic fibers and organic strength-improving materials to exert a nail side resistance of 500N or more, and the paper material covers at least the front and back surfaces of the main or core material. The surface density or surface weight, specified as the mass per unit area of ​​the wall surface, is 6.5 to 8.9 kg / m. 2 A gypsum-based load-bearing surface material having an area density or area weight within the range is fastened to the wooden structural wall substrate with a fastener, The ultimate displacement (δu2) of the bearing wall measured by an in-plane shear test using a bearing wall specimen with a wall length of 1.82 m is 20 × 10 -3 rad, and obtaining a corrected value (Pu') of the ultimate strength (Pu) calculated based on the ultimate strength (Pu) and plasticity factor (μ) of the shear wall measured by the in-plane shear test, the corrected value (Pu') being greater than 7.6 kN.

6. The construction method described in claim 5, characterized in that the thickness of the gypsum-based load-bearing surface material is set to a value less than 12 mm, or the specific gravity of the gypsum-based load-bearing surface material is set to a value of 0.96 or less, or the thickness of the gypsum-based load-bearing surface material is set to a value less than 12 mm and the specific gravity of the gypsum-based load-bearing surface material is set to a value of 0.96 or less.

7. 7. The construction method according to claim 5, wherein the measured value of the yield strength (Py) measured by the in-plane shear test is greater than 7.6 kN.

8. The corrected value (Pu') of the ultimate strength (Pu) is increased to a value of 8.0 kN or more, or the measured value (Py) of the yield strength measured by the in-plane shear test is a value of 8.0 kN or more, or the corrected value (Pu') is increased to a value of 8.0 kN or more and the measured value (Py) is a value of 8.0 kN or more. The construction method described in any one of claims 5 to 7.

9. A method for increasing the wall strength of a wooden structural wall constructed by fastening a gypsum-based shear surface material to the wooden structural wall base of a wooden framework construction method or a wooden frame wall construction method with fasteners, The load-bearing surface material is composed of a main material or core material made of a plate-shaped gypsum hardened body blended with inorganic fibers and organic strength-improving materials so as to exhibit a nail side resistance of 500 N or more, and a paper member covering at least the front and back surfaces of the main material or core material, The surface density or surface weight of the bearing surface material, specified as the mass per unit area of ​​the wall surface, is 6.5 to 8.9 kg / m 2 reduced to The ultimate displacement (δu2) of the shear wall measured by an in-plane shear test using a specimen with a wall length of 1.82 m was calculated as 20 × 10 -3 Ensure that the ultimate displacement (δu2) is greater than rad. The wall factor increasing method is characterized in that a corrected value (Pu') of the ultimate strength (Pu) obtained based on the ultimate strength (Pu) and plasticity factor (μ) of the shear wall measured by the in-plane shear test is set to a value greater than 7.6 kN.

10. The wall factor increasing method according to claim 9, characterized in that the thickness of the gypsum-based load-bearing surface material is set to a value less than 12 mm, or the specific gravity of the gypsum-based load-bearing surface material is set to a value less than 0.96, or the thickness of the gypsum-based load-bearing surface material is set to a value less than 12 mm and the specific gravity of the gypsum-based load-bearing surface material is set to a value less than 0.

96.

11. The method for increasing the wall factor according to claim 9 or 10, characterized in that the measured value (Py) of the yield strength measured by the in-plane shear test is greater than 7.6 kN.

12. The corrected value (Pu ') of the ultimate strength (Pu) is a value of 8.0 kN or more, or the measured value (Py) of the yield strength measured by the in-plane shear test is a value of 8.0 kN or more, or both the corrected value (Pu ') and the measured value (Py) are values ​​of 8.0 kN or more. A wall factor increase method according to any one of claims 9 to 11.

13. A gypsum-based load-bearing surface material for wooden structural walls that is fastened to the wooden structural wall substrate of a wooden framework construction method or a wooden frame wall construction method with fasteners. The bearing surface material is composed of a main material or core material made of a plate-shaped gypsum hardened body blended with inorganic fibers and organic strength-improving materials so as to exhibit a nail side resistance of 500 N or more, and a paper member covering at least the front and back surfaces of the main material or core material. The surface density or surface weight, specified as the mass per unit area of ​​the wall, is 6.5 to 8.9 kg / m 2 and having an areal density or areal weight in the range of The ultimate displacement (δu2) of the shear wall measured by an in-plane shear test using a shear wall specimen with a wall length of 1.82 m is 20 × 10 -3 The ultimate displacement (δu2) of the shear wall is greater than rad. The ultimate strength (Pu) of the shear wall measured by the in-plane shear test and the corrected value (Pu') of the ultimate strength (Pu) obtained based on the plasticity factor (μ) are greater than 7.6 kN. A gypsum-based shear surface material characterized by producing a corrected value (Pu') in the shear wall.

14. The gypsum-based load-bearing surface material described in claim 13, characterized in that the thickness of the load-bearing surface material is set to a value less than 12 mm, or the specific gravity of the load-bearing surface material is set to a value less than 0.96, or the thickness of the load-bearing surface material is set to a value less than 12 mm and the specific gravity of the load-bearing surface material is set to a value less than 0.

96.

15. 15. The gypsum-based load-bearing surface material according to claim 13, characterized in that it has a laminated structure in which the surface or surface layer of the core material is covered with gypsum board base paper.

16. The gypsum-based load-bearing surface material according to any one of claims 13 to 15, characterized in that the main material or core material of the gypsum-based load-bearing surface material contains an organopolysiloxane compound as a load-bearing deterioration inhibitor that prevents load-bearing deterioration.

17. The gypsum-based load-bearing surface material according to any one of claims 13 to 16, characterized in that the gypsum-based load-bearing surface material has a nail side resistance of 980 N or less.

18. The gypsum-based bearing surface material according to any one of claims 13 to 17, characterized in that the measured value (Py) of the yield strength measured by the in-plane shear test is greater than 7.6 kN.

19. The corrected value (Pu ') of the ultimate strength (Pu) is increased to a value of 8.0 kN or more, or the measured value (Py) of the yield strength measured by the in-plane shear test is a value of 8.0 kN or more, or the corrected value (Pu ') is increased to a value of 8.0 kN or more and the measured value (Py) is a value of 8.0 kN or more. The gypsum-based load-bearing surface material according to any one of claims 13 to 18, characterized in that

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